diff options
Diffstat (limited to 'kernel/drivers/pwm/pwm-twl.c')
| -rw-r--r-- | kernel/drivers/pwm/pwm-twl.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/kernel/drivers/pwm/pwm-twl.c b/kernel/drivers/pwm/pwm-twl.c new file mode 100644 index 000000000..04f76725d --- /dev/null +++ b/kernel/drivers/pwm/pwm-twl.c @@ -0,0 +1,352 @@ +/* + * Driver for TWL4030/6030 Generic Pulse Width Modulator + * + * Copyright (C) 2012 Texas Instruments + * Author: Peter Ujfalusi <peter.ujfalusi@ti.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/i2c/twl.h> +#include <linux/slab.h> + +/* + * This driver handles the PWMs of TWL4030 and TWL6030. + * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1 + * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2 + */ + +#define TWL_PWM_MAX 0x7f + +/* Registers, bits and macro for TWL4030 */ +#define TWL4030_GPBR1_REG 0x0c +#define TWL4030_PMBR1_REG 0x0d + +/* GPBR1 register bits */ +#define TWL4030_PWMXCLK_ENABLE (1 << 0) +#define TWL4030_PWMX_ENABLE (1 << 2) +#define TWL4030_PWMX_BITS (TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE) +#define TWL4030_PWM_TOGGLE(pwm, x) ((x) << (pwm)) + +/* PMBR1 register bits */ +#define TWL4030_GPIO6_PWM0_MUTE_MASK (0x03 << 2) +#define TWL4030_GPIO6_PWM0_MUTE_PWM0 (0x01 << 2) +#define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK (0x03 << 4) +#define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1 (0x03 << 4) + +/* Register, bits and macro for TWL6030 */ +#define TWL6030_TOGGLE3_REG 0x92 + +#define TWL6030_PWMXR (1 << 0) +#define TWL6030_PWMXS (1 << 1) +#define TWL6030_PWMXEN (1 << 2) +#define TWL6030_PWM_TOGGLE(pwm, x) ((x) << (pwm * 3)) + +struct twl_pwm_chip { + struct pwm_chip chip; + struct mutex mutex; + u8 twl6030_toggle3; + u8 twl4030_pwm_mux; +}; + +static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip) +{ + return container_of(chip, struct twl_pwm_chip, chip); +} + +static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1; + u8 pwm_config[2] = { 1, 0 }; + int base, ret; + + /* + * To configure the duty period: + * On-cycle is set to 1 (the minimum allowed value) + * The off time of 0 is not configurable, so the mapping is: + * 0 -> off cycle = 2, + * 1 -> off cycle = 2, + * 2 -> off cycle = 3, + * 126 - > off cycle 127, + * 127 - > off cycle 1 + * When on cycle == off cycle the PWM will be always on + */ + if (duty_cycle == 1) + duty_cycle = 2; + else if (duty_cycle > TWL_PWM_MAX) + duty_cycle = 1; + + base = pwm->hwpwm * 3; + + pwm_config[1] = duty_cycle; + + ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label); + + return ret; +} + +static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val; + + mutex_lock(&twl->mutex); + ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label); + goto out; + } + + val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE); + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); + + val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE); + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); + +out: + mutex_unlock(&twl->mutex); + return ret; +} + +static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val; + + mutex_lock(&twl->mutex); + ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label); + goto out; + } + + val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE); + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); + + val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE); + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); + +out: + mutex_unlock(&twl->mutex); +} + +static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val, mask, bits; + + if (pwm->hwpwm == 1) { + mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK; + bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1; + } else { + mask = TWL4030_GPIO6_PWM0_MUTE_MASK; + bits = TWL4030_GPIO6_PWM0_MUTE_PWM0; + } + + mutex_lock(&twl->mutex); + ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label); + goto out; + } + + /* Save the current MUX configuration for the PWM */ + twl->twl4030_pwm_mux &= ~mask; + twl->twl4030_pwm_mux |= (val & mask); + + /* Select PWM functionality */ + val &= ~mask; + val |= bits; + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label); + +out: + mutex_unlock(&twl->mutex); + return ret; +} + +static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val, mask; + + if (pwm->hwpwm == 1) + mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK; + else + mask = TWL4030_GPIO6_PWM0_MUTE_MASK; + + mutex_lock(&twl->mutex); + ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label); + goto out; + } + + /* Restore the MUX configuration for the PWM */ + val &= ~mask; + val |= (twl->twl4030_pwm_mux & mask); + + ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG); + if (ret < 0) + dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label); + +out: + mutex_unlock(&twl->mutex); +} + +static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val; + + mutex_lock(&twl->mutex); + val = twl->twl6030_toggle3; + val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN); + val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR); + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); + goto out; + } + + twl->twl6030_toggle3 = val; +out: + mutex_unlock(&twl->mutex); + return ret; +} + +static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct twl_pwm_chip *twl = to_twl(chip); + int ret; + u8 val; + + mutex_lock(&twl->mutex); + val = twl->twl6030_toggle3; + val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR); + val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN); + + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG); + if (ret < 0) { + dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); + goto out; + } + + twl->twl6030_toggle3 = val; +out: + mutex_unlock(&twl->mutex); +} + +static const struct pwm_ops twl4030_pwm_ops = { + .config = twl_pwm_config, + .enable = twl4030_pwm_enable, + .disable = twl4030_pwm_disable, + .request = twl4030_pwm_request, + .free = twl4030_pwm_free, + .owner = THIS_MODULE, +}; + +static const struct pwm_ops twl6030_pwm_ops = { + .config = twl_pwm_config, + .enable = twl6030_pwm_enable, + .disable = twl6030_pwm_disable, + .owner = THIS_MODULE, +}; + +static int twl_pwm_probe(struct platform_device *pdev) +{ + struct twl_pwm_chip *twl; + int ret; + + twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL); + if (!twl) + return -ENOMEM; + + if (twl_class_is_4030()) + twl->chip.ops = &twl4030_pwm_ops; + else + twl->chip.ops = &twl6030_pwm_ops; + + twl->chip.dev = &pdev->dev; + twl->chip.base = -1; + twl->chip.npwm = 2; + twl->chip.can_sleep = true; + + mutex_init(&twl->mutex); + + ret = pwmchip_add(&twl->chip); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, twl); + + return 0; +} + +static int twl_pwm_remove(struct platform_device *pdev) +{ + struct twl_pwm_chip *twl = platform_get_drvdata(pdev); + + return pwmchip_remove(&twl->chip); +} + +#ifdef CONFIG_OF +static const struct of_device_id twl_pwm_of_match[] = { + { .compatible = "ti,twl4030-pwm" }, + { .compatible = "ti,twl6030-pwm" }, + { }, +}; +MODULE_DEVICE_TABLE(of, twl_pwm_of_match); +#endif + +static struct platform_driver twl_pwm_driver = { + .driver = { + .name = "twl-pwm", + .of_match_table = of_match_ptr(twl_pwm_of_match), + }, + .probe = twl_pwm_probe, + .remove = twl_pwm_remove, +}; +module_platform_driver(twl_pwm_driver); + +MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>"); +MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030"); +MODULE_ALIAS("platform:twl-pwm"); +MODULE_LICENSE("GPL"); |